Process of dyeing



Patented May 21, 1935 UNITED STATES.

PATENT OFFICE PROCESS OF DYEING France No Drawing. Application June 11, 1931, Serial 10 Claims.

Although azo-dyestufis'containing a disulphide or trisulphide group in the molecule have already been described, the use of these dyestufis' for dyeing in a sulphide bath has involved difiiculties which do not appear to have been overcome. In particular the dyeings obtained on cotton are generally weak and the dyestuffs appear to have no aflinity for the material.

This invention is based on the discovery that these difliculties are due to the factqthat the dyestuiis are destroyed by the sulphide bath at a temperature which is generally lower thanthat commonly used in practice in dyeing with sulphur dyestufis. It is probable that the azo-linkage undergoes reduction by the sulphide which itself becomes oxidized; the quantity of sulphide in. the bath, therefore, decreases and may become insufficient for maintaining the unattacked dyestufi in solution. In consequence it is diflicult to obtain satisfactory dyeings. It may be noted that this behaviour is unexpected for it is known that sulphides in'general are not capable of reponent with the exception of fl-naphthylamine, or

again by the process described in my U. S. patent application Ser. No. 543,747 filed June 11, 1931, which consists in coupling the diazo-compound of an ortho-aminophenol with an azo compound containing atleast one dlor trisulphide group in the molecule. It has been found. unexpectedly 1 that the majority oi these dyestufls have a good afilnity for vegetable fibres and regenerated cellulose fibres, so much so that in many cases it is possible to obtain full dyeings even at ordinary temperature. For example, the dyestufi made in the manner described in German Specification No.

161,462 by coupling tetrazotized 4:4'-diamino- In France June 21, 1930 man specification. However, the latter shade may also be obtained, but in greater depth, when dyeing is conducted at ordinary temperature, it the dyestufi is allowed to remain for a long time in solution in presence of a sulphide either before 5 the addition of a small proportion of caustic soda or sodium carbonate, or less alkaline by the addition, for example, of sodiumhydrosulphide or sodium bicarbonate.

The invention is applicable not only for dyeing vegetable fibres but for dyeing fibres of regenerated cellulose or of cellulose ,ethers or cellulose esters.

The dyeings may subsequently be subjected to oxidation or to a treatment which is customary after dyeing or to more than one of these operations.

v The depth of the dyeings may be increased or their shade altered by subjecting the dyed goods to one or more repetitionsof the process either using the same dyestuif or a different dyestufl.

The following examples illustrate the inven tion the parts being by weight unless otherwise stated:

Example 1.One part of the dyestufi made by combining tetrazotized 2:2 dinitro 4:4 di aminodiphenylsulphide with p-naphthol (see. German specification No. 161,462) is dissolved at ordinary temperature in 5 parts by volume of a solution containing 2 parts of crystallized sodiu-m sulphide and the solution is diluted by the addition of 150 parts by volume of a solution containing 22.5 parts of crystallized sodium sulphate. 10 parts of cotton are introduced into the bath and maintained in motion therein during one hourat ordinary temperature. The material is then washed and subjected to oxidation, for example by means of a dilute solution by hydrogen peroxide. A full orange shade is obtained whereas if cotton is dyed in the hitherto usual manner with the'same dyestufi only a weak bluish-red shade is obtained.

In like manner dyeing may be conducted with phonated oils and other substances adapted to no chloride or the like;

Example 3.--50. 5 parts of the dyestufi obtained by coupling tetrazotized para:para'-di- 7 Colour oi dyeing on cotton, ami- 5 Coupled with 2 molecular proportions ol oxidation Tetrazo-oompoundoi 2z2'1 l i nitro-l-zy-diamino-diphenyldisulphide grown-yellow.

Meta-phenylenediamine fl-na hthnl rang 2:7 ydroxynaphthalene"; Brown-orange. Phenylmethylpyrazolone Yellow. fi-naphthol Vlad yellowish- Dn -na'nhflml Brown-purple.

2:7-dihydro phthalene Brown.

Meta-phony enediamine grain-yellow.

Dn Dn izlgaminodiphenyl disulphide (para-parW-dithioaniline). fi-oxynaphthoic acid-parazparamthioanilide Bis(2 hydroxynaphtyl 6) disulphide Red. D 'lrisulphide oi a-naphthol Red-purple. Anili Red.

Bh ydroxynaphtboic acld-para:pera'-dithioanilide The conditions indicated in the foregoing exthioaniline with a-naphthylamine (compare Example may be varied within wide limits. The

ample 2 of U. S. patent application Ser. No. 543, dyestufl! may be used in a different concentration, 146 filed June 11, 1931) are dissolved in 25 parts the concentration of sodium sulphate or other by volume of a solution containing 10 parts of metal salt may be, increased or reduced. There crystallized sodium sulphide and there are then may beadded to the dye-bath a. neutralizing added3'15 parts by volume 0! a cold solution conagent, such as sodium bicarbonate or sodium hytaming I12 parts of crystallized sodium sulphate. drosulphide, or an agent which renders the bath 25 parts of cotton are dyed for 30 minutes at more alkaline, such as sodium carbonate or causordinary temperature in the bath so prepared. tic soda. There may also be'used any oithe vari- After oxidation a brown dyeing isobtained. It ous additions usual in dyeing, such as glue, sulmay be diazotized in the usual manner in a bath containing nitrous acid and then introduced into improve the penetration of the fibre or to hinder 'a' feebly alkaline bath containing p-naphthol; a the precipitation of the dyestufl. The dyeing, black shadeisthus obtained. The diazotized dyemay be oxidized by means of atmospheric oxygen, ing may of course be coupled with other azodyea very'dilute solution of sodiumfhypochlorite, ferstufi coupling components.

Example 4..The procedure is as described in L Example 1 with the exception that instead of or the dyeing Operation y ndu ted alla adding the solution of sodium sulphate imhigher temperature which must, however, belowmediately after dissolution of the dyestuil, the er than that atwhich the dyestufl is destroyed or solution oi the dyestuflf is first allowed to stand altered. for 3 hours. The dyeing thus obtained, instead of Example 2.One part of the dyestufi obtained being orange, is red. I by coupling diazotized 4-chlor o-2-amin0-1- Example 5.Cellul0se regenerated from viscose phenol with s-hydroxy-naphthoic acid para: is dyed inthe manner indicated in Example 1 pam'rdithioanilide (compa e a ple 3 01 with the dyestuil' from tetrazotized par'azparBJ- French patent application No 297,526 filed June dithioaniline and p-naphthol. The shade is fuller 1 is di solved in 2 parts of caustic soda and its iastness to light greater than in the case solution of 36 B. and 5 parts of a solution conof the dyeing on cotton. taining z parts of crystallized sodium sulphide Ezample 6.Artiflcial silk oi. acetyl cellulose and there are t n added 170 P r y vo is dyed inthe manner indicated in Example 1, the

D izfl-gaminodiphenyldisulphide (para-pard-dithioaniline) 10 In the case of certain the dissolution solution n n Parts Of 'fil'ystflllized duration of the dyeing operation, however, be-

sodiinn sulphate. 10 parts of cotton are dyed-by m increased to 2 s. There is obtained a 50 immersion for '50 minutes at ordinary tempera;- turein the dye-bath so prepared. By oxidation S g P red without alteratio of the dyeing, for example by means oi. dilute A blulshqed shade is obtained by using the dyestufl from tetrazotized dithioanaline and hydroxynaphthoic aciddithioanilide. Example 7.Cotton' is dyed in the manner indicated in Example 1 with the dyestufl' rom' tetrazotized dithioaniline and p-naphthol. After bluish-red shade, By subsequent" treatment of the dyeing with a solution of a copper salt,-such as copper sulphate, and acetic acid there is obtained a violet shade of remarkable fastn'ess to light. As in the preceding example the con-r ditions of dyeing may be substantially modified. dyeing by means-0f Th properties 1 number of dyemgs bt i gen peroxide, the dyed cotton is re-introduced able by the invention and'atter treated with metal into the same dy e and y in the Same salt a m t d i t following t m manner as before. The depth oi the red dyeing himor tetraaocomponent Coupled with- Vivid red. Brownish-red. Bordeaux. Violet-red. Darkviolet. Bordeaux. Violet. Brown-red.

, said dyestufl at a temperature lower than is thus increased. dyeing operation may be repeated several times.

Example 8.-'lhe fibre which has been dyed red in the manner described in Example 1 by means of the dyestufl from tetrazotized para:para'- dithioaniline and s-naphthol, is introduced after the oxidation into a second dye-bath prepared in the same manner with the dyestufl from tetrazotized para:para'-dithioaniline and methylphenylpyrazolone (Example 1 of U. S. patent application Ser. No. 543,746 filed June 11, 1931). An orange red shadeis thus obtained.

What I claim is:

1. A processor dyeing materials which comprises treating said materials in a sulphide bath by an azo-dyestuff containing at least one disulphide group in the molecule at a temperature lower than 65 C.

2. A process of dyeing materials which comprises taking the dyestufl resulting from the coupling of the tetrazo compound of 4:4-diaminodiphenyldisulphide (para para dithioaniline) with meta-phenylenediamine, dissolving it at a temperature lower than 65 C. in a solution of crystallized sodium sulphide, adding a solution containing sodium sulphate, introducing the material to be treated into the bath thus obtained, allowing it to remain therein for a certain time, washing it and'oxidiz'ingit.

3. A process of dyeing materials which comprises taking the dyestuflf resulting from the coupling of the tetrazo compound of 4:4'-diaminodiphenyldisulphicle (para-para' dithioanillne) with p-hydroxynaphthoic acid para:para-dithioanilide, dissolving it1at a temperature lower than 65 C. in a solution of crystallized sodium sulphide, adding a solution containing crystallized C. in a solution of crystallized sodium sulphide, adding a solution containing crystallized sodium sulphate, introducing the material to be treated into the bath thus obtained, allowing it to remain therein for a certain time, washing it and oxidizing it. g

5. A process of dyeing materials which comprises taking the dyestufi resulting from the coupling of an azo-compound of nitro-orthoaminophenol with p-hydroxynaphthoic acid-dithioanilide, dissolving it at a temperature lower than 65 C. in a bath containing a caustic soda solu: tion, and a solution of crystallized sodium sulphide, adding a solution of crystallized sodium sulphate, immersing into the bath thus obtained the material to be treated, and oxidizing the dyed material.

6. A process of dyeing materials which comprises treating said' materials in a sulphide bath by an azo-dyestufi containing at least one disulphide group in the molecule, -at a temperature lower than 65- C., oxidizing the dyed material and treating it with another dye-bath.

7. A process of dyeing materials which comprises treating said materials in a sulphide bath by an azo-dyestuff containing at least one group Sn, in whichn equals 2 or 3 at a temperature lower than 65 C.

8. A process of dyeing materials which comprises treating said materials in a sulphide bath by an azo-dyestuflf containing one disulphide group in the molecule, at a temperature lower than 65 C.

9. A process of dyeing materials which comprises treating said materlals in a sulphide bath by an a'zo-dyestufi resulting from the coupling of a diazotized ortho amino phenolwith an azocomponent containing at least one disulphide group in the molecule, at a temperature. lower than 65 C. I

I 10. A process of. dyeing materials which comprises treating said materials in a sulphide bath by an azo-dyestufl containing two disulphide 

